Scoreboard
Lee King, Henry Johnson, Demetrius Jackson, Bennie Chandler, Marcus Rice
Parts List
3-Green LED’s
Resistor
2-Red LED’s
Resistor
5-330 Ohm Resistors
2-74175 OR Gate
3-1 k ohm Resistors
2-NO Push Buttons
2-555 Timers
1-0.01 uf Capacitor
1-0.1 uf Capacitor
1-10 k Ohm Resistor
1-22 k Ohm
1-1.0 M Ohm
Information
A counter uses flip-flops to “remember” the last count until the clock pulse occurs.
A shift register can store several events in series depending on the length of the register.
A shift register such as a Johnson counter, can be set with a characteristic sequence like a counter and can be used in applications requiring a counter. This experiment requires two count sequences.
Either can be completed first. The one completed first must clear both clear both counters.
The counters are “clocked” manually by pushbuttons. 555 Timers
Design
The logic function of the circuit can be designed by using a simple D flip flop counter.
The logic function may also be created by:
1. Creating a state diagram of binary counts
2. Using a transition table, populate present and next state tables
The lab calls for a 74175 IC chip to be used as the counting device. Since we will be counting two separate counts, one for strikes and one for balls,
TWO 74175 IC chips will be used.
Work in progress
More Information
We had to use 4 of the 7474 in place of the 74125
The CLR triggers when either Q2 OR Q7 the CLK is connected to the Pushbutton circuit. D0 is connected to
+5V. D1 is connected to Q0. D2 is connected to Q1. For the
Balls counter; D4 is connected to +5V. D5 is connected to
Q4. D6 is connected to Q5. D7 is connected to Q6
The 74175 IC chip contains 4 D flip-flops. Knowing this we can feed the output of the first into the input of the next forming a counter. Applying a positive voltage +5V on D1 and connecting the CLK to a +5V when the STRIKE BUTTON is pressed to cycle the counter. The